Turning Water and Sun into Electricity with a Synthetic Leaf

Leaves are the original solar collector. The trick has always been to duplicate their efficiency. Now it looks like that may be possible. An MIT group (headed by Professor Daniel Nocera) announced at the 241st National Meeting of the American Chemical Society, a successful solar cell that artificially recreates the process of photosynthesis.

The leaf offers the following potential benefits:

1. Cheap:The poker card-shaped leaf is made up of silicon, electronics, catalysts, and chemicals. It utilizes inexpensive materials such as nickel and cobalt.

2. Simple: Place the leaf in single gallon of water in bright light. Then the leaf can split the water into hydrogen and oxygen, creating a source of energy.

2. Output is consistent: It can produce enough electricity to supply a house in developing country for a day.

Nocera claims that this artificial leaf is 10 times more efficient than photosynthesis in a real leaf. Granted, no energy conversion is truly 100% efficient, but if this artificial leaf delivers, this technology has the potential to revolutionize what we think of energy.

Imagine the endless possibilities!

The following video is Dr. Daniel Nocera explaining his method in 2008:

About Wen Duan

Wen studies electrical engineering and computer science at UC Berkeley, works as an IT, and participates in high-performance computation research. Along with consuming an absurd amount of television, movies, and books, she is infatuated with making the web her source of media as well as sharing them with anyone she can!

Comments

Great. So you take this fake leaf and send it to a country where water is at a premium and tell them to shove it in a gallon of water. “Ok Mr Thirdworldman, here’s how it works. You get your wife to carry an extra gallon of water from the river 15 miles away and you can use it to make electricity!”.

The leaf may be 10 times more efficient than real photosynthesis, but seeing as we don’t use real plants to generate electricity that’s not a reasonable comparison. How does the leaf compare to a similar sized regular solar cell in terms of both cost and power generated? Then factor in the cost of the water in terms of (3rd world) human effort and (the rest of us) price.

This really just appears to be the result of some academic trying to justify their grant and maintain the ability to play Angry Birds during the working day.

Thanks for reading the article! You make some very valid points. Some of which got me thinking of things I failed to address:

According the Betz’ Law windmills only produce 59 percent of efficiency in ideal conditions , but in real life it’s only at best 40% efficiency. Even if photosynthesis is only 2-5% efficient energy conversion 10x is still 20%-50% efficient energy conversion.

It’s true that photosynthesis through leaves is not a commonly used, but the splitting of hydrogen and oxygen is not only safe but also a method of converting energy into electricity: http://en.wikipedia.org/wiki/Water_splitting

Plus water and sunlight is readily (almost) everywhere. Because where there is water and sunlight there is most likely people. To transport a card versus a windmill or solar power is more realistic and cheaper as well. But granted water is very valuable, but it is more readily available and cheaper than things like gasoline or propane gas for certain generators.

You have a higher chance of finding free water in the world than you do gas. And you cannot get energy without a price.

Lastly, though I do not know Professor Daniel Nocera personally, but I do know that he is one of the most acknowledged researchers in alternative energies… to the point where most researchers interested in alternative sources of energy at least heard or read one of his 225 published papers.